title: [Catalytic properties of E. coli tryptophanase in a 50% aqueous solution of methanol and dimethylformamide].
abstract: Tryptophanase from E. coli retains its ability to form quinonoid intermediate with L-alanine in water--methanol and water--dimethylformamide (1:1 v/v) solutions. Under these conditions the enzyme catalyzes decomposition of S-o-nitrophenyl-L-cysteine (SOPC) to o-nitrophenylthiol, pyruvate and ammonium ion. The enzyme's affinity for this substrate increases on going from water to water-organic solvents whereas the reaction rate decreases. In 50% methanol tryptophanase catalyzes the formation of L-tryptophan from indole and SOPC; in the mixture of 2H2O and C2H3O2H (1:1) the enzymatic isotope exchange of alpha-proton of L-phenylalanine with complete retention of configuration was observed.
authors.forename: N G
authors.initials: NG
authors.lastname: Faleev
authors.forename: M B
authors.initials: MB
authors.lastname: Saporovskaia
authors.forename: V M
authors.initials: VM
authors.lastname: Belikov
authors.forename: I S
authors.initials: IS
authors.lastname: Sakharova
authors.forename: L N
authors.initials: LN
authors.lastname: Zakomyrdina
authors.forename: Iu M
authors.initials: IuM
authors.lastname: Torchinskiĭ
mesh_terms: D002384:Catalysis; D004126:Dimethylformamide; D004926:Escherichia coli / Q000201:enzymology*; D007700:Kinetics; D000432:Methanol; D012997:Solvents; D013056:Spectrophotometry, Ultraviolet; D013379:Substrate Specificity; D014368:Tryptophanase / Q000737:chemistry* / Q000378:metabolism
chemical_list: D012997:Solvents; D004126:Dimethylformamide; D014368:Tryptophanase; D000432:Methanol
vernacular_title: Kataliticheskie svoĭstva triptofanazy iz E. coli v 50% vodnykh rastvorakh metanola i dimetilformamida.